Joran van der Sloot will plead guilty to killing 21-year-old Stephany Flores Ramirez in Peru last May, but will argue temporary insanity, according to reports.

The Dutchman, 23, will try for a reduced sentence using the "violent emotion" defense, his lawyer, Maximo Altez, told The Associated Press.

The lawyer argues that Van der Sloot killed Ramirez on May 30 after becoming enraged when he realized she had looked at his laptop and learned of his connection to missing American teen Natalee Holloway, who disappeared from the island of Aruba in 2005.

Ramirez, a Peruvian business student, was found bludgeoned to death in a Lima hotel room. Van der Sloot stands accused of first-degree murder – in Peru that means a 15- to 35-year sentence if convicted. But if his insanity defense holds up, Van der Sloot could serve only 20 months of a 3-5-year sentence, Altez told the AP.